__author__ = 'wangzk'
"""有1、2、3、4
个数字，能组成多少个互不相同且无重复数字的三位数？都是多少
"""
a_list = [1,2,3,4]
result = []
for a in a_list:
    b_list = [1,2,3,4]
    b_list.remove(a)
    for b in b_list:
        c_list = [1,2,3,4]
        c_list.remove(a)
        c_list.remove(b)
        for c in c_list:
            result.append(str(a)+str(b)+str(c))
print(result)
print(len(result))